I love Radio Shack. I’ve been shopping there since I was a kid. They have all of the stuff that techno-geeks crave. Gear, toys, things you can build circuits with .–everything for the wirehead in all of us.

That’s the good news. Unfortunately, Radio Shack (like all retailers) has to compete for your hard-earned dollars so, like all retailers, they run promotions. Buy now, pay later! No interest for 12 months, etc.

Also, like many major retailers, they have a deal with a bank (in Radio Shack’s case, Citibank) to handle the financial aspects of their promotions. After all, they are not really waiting a year to get paid, and they are not borrowing the money interest-free. This shouldn’t be news to anyone.

The news is in the “fine print.” Miss one minimum monthly payment of $12 dollars and you’ll see a $35 dollar late charge and $108 interest charge added to the balance on your $400 DVD player. So instead of getting a promotional rate, you now owe 35 percent more than the sale price of your purchase. Even if you now make the monthly payments, the new finance charges will accrue on your total balance. You could end up paying $700-800 for a $400 DVD player by missing one $12 minimum monthly payment.

No problem you say, just stick to the payment terms and everything will be OK. Not true. The grace period for this kind of payment is extremely small–and the window of time that customer service will treat you like a human being is even smaller. Any mistake can cost you literally a 100 percent surcharge on your purchase.

Hey, it’s the 21st century—so, set the payment up a radioshack.com. Nice try. One Internet glitch and you won’t know your payment was not received until your next statement. And by then it’s too late. The terms of the “promotion” are ironclad. Miss a payment and all of the accrued interest and late fees apply.

Radio Shack must have been absent from business school the day they taught customer service, because the dunning phone calls from Citibank are exceptional. The “collection” people are rude, they can’t answer questions outside of their script, and they have no authority to solve problems. Their only job is to get you to settle up on the phone.

One might assume that before outsourcing a critical function like consumer relationships, Radio Shack would have thought through the idea that scamming or otherwise torturing regular customers was a bad idea. I guess not.

Radio Shack has trained consumers not to buy anything of substance from them unless they are running a sale. As consumers know, there is a holiday sales event every month (except August, when retailers run “back to school” sales). So these promotional scams run literally all year long.

How long can companies like Radio Shack continue to scam their customers with artificially low sale prices, only to crush them with late fees and accumulated interest? For all of their database experience, Radio Shack seems to know nothing about their core customers. I can speak from experience; I used to be one.